The Synthetic Antigen Facility provides synthetic peptides in a highly purified state to faculty members of the University of Texas M.D. Anderson Cancer Center. This facility is located in room B8.4806 (544 feet/2) and is equipped with a special enhanced exhaust system for handling HF. Facility staff members provide consultation to the research staff regarding synthetic peptides. The institution is provide new peptide synthesizers and high-performance liquid chromatography (HPLC) equipment that will double the facility's current capacity and decrease its turnaround time. Funds from the facility's charge-back account cover the cost of materials and the salary for one research investigator. An oversight committee exists consisting of John McMurray, P.h.D., Benoit deCrombrugghe, M.D., and Ralph Arlinghaus, P.h.D. The major functions of this committee are to review the operation of the facility, make suggestions for improvement, set priorities, and ensure the satisfaction of the users. Ninety-three of the 122 peptides made last year (7/1/96 to 6/30/97) were produced for peer-funded investigators, reflecting the facility's goal to provide high-quality reagents to the most competitive and productive faculty members. These peptides were provided to a total of 21 users, 14 of whom were peer funded. Since the last competitive renewal, 936 peptides were synthesized, 612 of which were for peer-funded users (7/1/91 to 6/30/97). In general the purity of the peptides provided to users was routinely 90% or higher,a nd some peptides were supplied at a purity greater that 95%. One example of the type of peptides supplied this past year is a 42-amino-acid peptide synthesized for Dr. Larry Etkin (Department of Molecular Genetics). The sequence of this peptide was derived from a unique zinc-finger domain discovered by Dr. Etkin. Research studies involving this peptide by a physical chemistry group in London, England, established the structure of this domain. The key factors were the large amount of peptide supplied and the low cost compared with costs of outside competitors. Another examine is a phosphotyrosine peptide supplied to Dr. Gordon Mills (Department of Molecular Oncology). This synthesis required an alternative method of phosphorylation from that used by many in the field. Normally, the phosphate is added to the Y residue after synthesis, but because of the presence of oxidation-sensitive residues (e.g., two methionines), a protected, phosphorylated amino-acid derivative was used for the synthesis phase (tBOC dimethylphosphotyrosine). The phosphotyrosine peptide was provided at 98% purity.